Project description:Reactivation of the telomerase reverse transcriptase subunit, TERT, is linked to tumourigenesis due to well-documented telomere-dependent and independent functions. The aim of this study was to investigate the effect of the telomerase inhibitor, MST-312, on TERT functions, focusing in particular, on its effects on MYC stabilty and MYC-regulated pathways, in order to assess its potential as a therapeutic agent. We demonstrate that MST-312 reduces MYC levels in cancer cells, leading to reduced MYC levels on chromatin, and subsequently affecting the MYC-regulated transcriptional program. As a result, MST-312 treatment increases the survival of lymphoma-bearing mice. Mechanistically, MST-312 affects the conformation of TERT, leading to TERT/Terc dissociation, and the subsequent loss of both its telomere-dependent and independent functions. Based on the presented data, we conclude that MST-312 treatment is a promising therapeutic strategy, in particular, in MYC-driven tumorus.
Project description:Reactivation of the telomerase reverse transcriptase subunit, TERT, is linked to tumourigenesis due to well-documented telomere-dependent and independent functions. The aim of this study was to investigate the effect of the telomerase inhibitor, MST-312, on TERT functions, focusing in particular, on its effects on MYC stabilty and MYC-regulated pathways, in order to assess its potential as a therapeutic agent. We demonstrate that MST-312 reduces MYC levels in cancer cells, leading to reduced MYC levels on chromatin, and subsequently affecting the MYC-regulated transcriptional program. As a result, MST-312 treatment increases the survival of lymphoma-bearing mice. Mechanistically, MST-312 affects the conformation of TERT, leading to TERT/Terc dissociation, and the subsequent loss of both its telomere-dependent and independent functions. Based on the presented data, we conclude that MST-312 treatment is a promising therapeutic strategy, in particular, in MYC-driven tumorus.
Project description:Chromatin immunoprecipitation sequencing (ChIP-seq) was performed to analyze the effect of telomerase inhibition on TNFM-NM-1-induced genome-wide p65 binding in HeLa cells. By obtaining over 40 million uniquely mappable reads per sample from ChIP-seq, maps for TNFM-NM-1-induced p65 binding in absence and presence of an hTERT inhibitor, MST-312, were generated. As expected, TNFM-NM-1 treatment significantly increased genome-wide p65 occupancy. Interestingly, when cells were treated with MST-312 prior to TNFM-NM-1 stimulation, the number of p65 binding sites was reduced. In addition, some binding sites, including important p65 targets like IL6 and TNF, showed a reduced p65 occupancy with a minimum fold change of 1.5, after MST-312 exposure. Taken together, our ChIP-seq data indicate that telomerase is required for optimal p65 binding at a small proportion of p65 target sites upon inflammatory stimuli. Examination of p65 binding in HeLa cells in absence and presence of TNFM-NM-1 and MST-312.
Project description:Chromatin immunoprecipitation sequencing (ChIP-seq) was performed to analyze the effect of telomerase inhibition on TNFα-induced genome-wide p65 binding in HeLa cells. By obtaining over 40 million uniquely mappable reads per sample from ChIP-seq, maps for TNFα-induced p65 binding in absence and presence of an hTERT inhibitor, MST-312, were generated. As expected, TNFα treatment significantly increased genome-wide p65 occupancy. Interestingly, when cells were treated with MST-312 prior to TNFα stimulation, the number of p65 binding sites was reduced. In addition, some binding sites, including important p65 targets like IL6 and TNF, showed a reduced p65 occupancy with a minimum fold change of 1.5, after MST-312 exposure. Taken together, our ChIP-seq data indicate that telomerase is required for optimal p65 binding at a small proportion of p65 target sites upon inflammatory stimuli.
Project description:Gene expression changes of UC-model organoids derive from human colon indcued by telomere enlongation was assessed by Madecassoside treatemt (telomerase activator). Gene expression changes of human colon organoids induced by telomere shortening was assessd by MST-312 treatment (telomerase inhibitor).
Project description:Quercetin is a natural flavonoid with well-established anti-proliferative activities against a variety of cancers. Telomerase inhibitor MST-312 also exhibits anti-proliferative effect on various cancer cells independent of its effect on telomere shortening. However, due to their low absorption and toxicity at higher doses, their clinical development is limited. In the present study, we examine the synergistic potential of their combination in cancer cells, which may result in a decrease in the therapeutic dosage of these compounds. We report that MST-312 and quercetin exhibit strong synergism in ovarian cancer cells with combination index range from 0.2 to 0.7. Co-treatment with MST-312 and quercetin upregulates the DNA damage and augments apoptosis when compared to treatment with either compound alone or a vehicle. We also examined the effect of these compounds on the proliferation of normal ovarian surface epithelial cells (OSEs). MST-312 has a cytoprotective impact in OSEs at lower dosages, but is inhibitory at higher doses. Quercetin did not affect the OSEs proliferation at low concentrations while at higher concentrations it is inhibitory. Notably, combination of MST-312 and quercetin had no discernible impact on OSEs. These observations have significant implications for future efforts towards maximizing efficacy in cancer therapeutics as this co-treatment specifically affects cancer cells and reduces the effective dosage of both the compounds.
Project description:Hepatocellular carcinoma (HCC) is a relatively chemo-resistant tumor. Several multi-kinase inhibitors have been approved for treating advanced HCC. However, most HCC patients are highly refractory to these drugs. Therefore, the development of more effective therapies for advanced HCC patients is urgently needed. Stathmin 1 (STMN1) is an oncoprotein that destabilizes microtubules and promotes cancer cell migration and invasion. In this study, cancer genomics data mining identified STMN1 as a prognosis biomarker and a therapeutic target for HCC. Co-expressed gene analysis indicated that STMN1 expression was positively associated with cell-cycle-related gene expression. Chemical sensitivity profiling of HCC cell lines suggested that High-STMN1-expressing HCC cells were the most sensitive to MST-312 (a telomerase inhibitor). Drug-gene connectivity mapping supported that MST-312 reversed the STMN1-co-expressed gene signature (especially BUB1B, MCM2/5/6, and TTK genes). In vitro experiments validated that MST-312 inhibited HCC cell viability and related protein expression (STMN1, BUB1B, and MCM5). In addition, overexpression of STMN1 enhanced the anticancer activity of MST-312 in HCC cells. Therefore, MST-312 can be used for treating STMN1-high expression HCC.